Well, don't make Wick the farthest point North you go is what I mean, before anyone from FarNorth Aviation at Wick comes on to complain.
Can't help you with the route south of Edinburgh, but:
If the wx is reasonable, go direct over the mountains from Perth to Inverness - the view is spectacular and Inverness is a pretty friendly airport and I would bet serious money it's cheaper than Aberdeen (fuel and landing fees). Again, spectacular scenery up the coast from Inverness to Wick. Wick town is OK and I'd reccommend a visit, but push north to Kirkwall - it's only about 20 minutes further and more geared up for tourists (slightly more history / accommodation / pubs
You might also then consider doing some island hopping - Westray to Papa Westray is the shortest scheduled air route in the world - even in a Cessna my time in the air was 90 seconds across the water - great one for the log book!
Enjoy!